Effective removal of glyphosate from water by resin-supported double valent nano-sized hydroxyl iron oxide

Abstract

The double valent composite resin (DR) was prepared within nano-sized Fe(II) and Fe(III) hydroxyl oxide crosslinking polystyrene anion exchanger resin for efficient glyphosate removal from water. The structure, morphology, Fe species, crystal phase, and elemental composition of the prepared DR composites were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The effects of contact time, pH, temperature, coexisting anions and regeneration were studied in batch mode. It was found that a low pH value favors the adsorption of glyphosate, and the adsorption kinetics were well fitted by a pseudo-second-order model. The exhausted DR composites could be regenerated by NaOH solution for repeated use without any significant capacity loss, where the adsorbed glyphosate was effectively desorbed into the solution. Fixed-bed adsorption further validated that DR composites would be of considerable potential in the removal of glyphosate from contaminated waters.